Formation of nanostructures by self-assembly of soft material molecules such as colloids, block copolymers, surfactants, supramolecules or the like has been studied for a long time. It is possible to form a variety of nanostructures based on the structures, shapes, interactions or the like of molecules themselves, and the use of nanostructures has an advantage in that it enables the development of effective nano-patterning technology. Studies on the formation of nanostructures using block copolymers among such soft material molecules have been actively conducted. However, in current technologies, a process of fabricating ordered structures over large areas is complex and requires a long time (a few hours), and thus there is a limitation in terms of commercial applications.
In the academic world, studies on the self-assembly properties of tapered organic supramolecules have been actively conducted in order to overcome the shortcoming of slow reorientation of block copolymers and to obtain stable structures having a smaller size (about 5 nm or less). On the other hand, self-assembly methods using liquid crystal molecules have the advantages of conventional patterning technology, including easy fabrication, ordered alignment over large areas, various sizes, etc., and also have a great advantage in that, because of the characteristic high mobility of liquid crystal molecules and the fast response of liquid crystal molecules to external fields, the processing speed of liquid crystal molecules is several tens of times higher than that of other self-assembled materials studied previously, and the structure can be easily controlled.
Supramolecular dendrimers having thermotropic liquid crystal properties are self-assembled to form cylindrical structures within a very short time, and nanostructures thereof have a feature size of several nm (<5 nm), which is very smaller than that of block copolymer nanostructures (several tens to several hundreds nm). Thus, it is expected that when supramolecular dendrimer nanostructures having such advantages are used as lithographic templates, they will overcome the limitations of block copolymers.
In particular, such cylindrical structures vertically aligned on substrates have received a great deal of attention, because these structures can be used as optoelectronic materials, selective membranes and nanopatterning templates. For this practical use, it is important to orderly align organic supramolecular cylindrical structures over large areas, but there has been difficulty in creating a vertical alignment of large-area single domains.
Korean Patent No. 1252506 discloses a polyacetylene supramolecular sieve having selectivity for lead ions. This Korean Patent discloses a method of detecting lead ions using the polyacetylene supramolecular sieve, but does not disclose a method for aligning supramolecules.
Korean Patent Registration No. 0778011 discloses a method of fabricating metal nanowires using self-assembled supramolecules. This Korean Patent discloses a method of fabricating metal nanowires using supramolecular hexagonal nanostructures, but has a shortcoming in that the use of non-metallic supramolecules is impossible, because columnar structures are formed using a combination of metal ions and supramolecules.
Accordingly, the present inventors have made extensive efforts to overcome the above-described problems, and as a result, have found that columnar or lamellar structures of organic molecules aligned into a large-area single domain are obtained by attaching organic molecules to a bottom substrate, and then covering the organic molecules with a top substrate to spatially confine the organic molecules between the bottom substrate and the top substrate, and heating the spatially confined organic molecules above the isotropic transition temperature of the organic molecules, thereby completing the present invention.